Sympatric speciation
i. is common in animals but rare in plants.
ii. initially involves a physical geographic separation of individuals from a single population into two separate populations.
iii. can result in the formation of a new species within a few generations.

The correct answer is III. can result in the formation of a new species within a few generations.

Explanation:

When a population from a species who live in the same habitat isolate reproductively and form new species then this process is known as sympatric speciation. This speciation mainly results from the generation of polyploidy condition.

In polyploidy condition the chromosome numbers in the individuals become double. This condition most commonly occurs in plants. Then these polyploid plants can not reproduce with other diploid plants but can fertilize itself so it create a reproductive isolation with other members and produce new species. So in sympatric speciation formation of new species occurs within a few generations.

answer; i believe the correct answer is ( proteins );

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.